The printed wiring board (PWB) is a vital component of electronic equipment. Today, with product diversification and a shorter development cycle being dominant trends, it is essential to develop PWBs that satisfy performance and reliability requirements as quickly as possible. It has therefore become important to correctly select and appropriately use PWB materials that suit objectives from among the many commercially available materials. Over the last ten years, Fujitsu has been independently evaluating insulation materials for PWB use and has been comparing those results with the results of evaluating PWBs themselves while performing tests and accumulating data. We are currently developing evaluation technologies for determining whether new insulation materials can achieve the performance demanded of PWBs used in a variety of Fujitsu products. Among these technologies, we introduce ones that target thermomechanical properties, heat resistance, and transmission properties and mention their future directions.